Paper Feed Mechanism - Epson Stylus Color 1520 Service Manual

EPSON Stylus COLOR 1520

2.2.4 Paper Feed Mechanism

The paper feed mechanism of this printer consists of the integrated ASF (Auto Sheet Feeder), tractor, PF
(Paper Feed) motor, front/rear PE (Paper End) sensors, PF roller, paper guide mechanism, paper eject unit,
and PF motor drive disengage mechanism. Torque from the PF motor is transmitted to load, feed and eject
paper. While the printer is not printing, the disengage mechanism switches torque from the PF motor to the
pump mechanism. While paper is being fed, the PF motor transmits torque via the PF motor pinion gear and
disengage gear to the PF roller, where torque goes 2 directions. One is to the paper eject mechanism via the
gear train in the paper guide assembly. The other is to the ASF mechanism via the transmission gear.
The tractor drive gear train is set at the left end of the PF roller. Table 2-4 and Table 2-5 show the
specifications for the PF motor and drive terms. Figure 2-5 illustrates the paper feed mechanism.
Item
Motor type
Drive voltage
Coil resistance
Connection
Excitation mode
Minimum step
Operation
mode
Paper feed
(Line feed:6/1 inch)
ASF Feed
Pump driven
Pump driven
(slow)
Note) Double 1-2 phase drive / 2-2 phase drive
2-6
Table 2-4 PF Motor Specification
4-phases / 96-pole / HB-type pulse motor
42 VDC ± 5%
10 Ω ± 10% at 77° F (25° C) per phase
Bipolar
2-2 phase, 1-2 phase, W1-2 phase constant current drive
1/720 inch / step (2-2 phase drive)
Table 2-5 PF Motor Drive Terms
Acceleration Constant
0.9/0.9
0.9/0.9
 /0.9
 / 
Description
Deceleration
0.9 0.75/0.75
0.9 0.75/0.75
0.9 0.9
 / 
0.9
Stand-by
0.6
0.6
0.6
0.6